SAMSUNG HP-T5064X/XAA sound with no image - failed power board BN44-00162A...or not?

Note: below is a correspondence between us and a customer regarding his Samsung HP-T5064.

100% of what is said applies to the more popular model HP-T5054 as well as actually most other plasma TVs manufactured about the same time.

There's more to be said about them and I will maybe post another article about it, but this time the focus is on the common mistake I see of blaming the power board after reading a few misleading (and ofter confused by themselves) opinions by "experts" on sites like FixYa or Answer.com.

02 February 2014 update: We just posted an article showing how to test power supply boards BN44-00161A, BN44-00162A , BN44-00160A and others.



Customer:
Dear Coppell TV Repair,
I have a Samsung HP-T5064X/XAA and I believe I have a failed SMPS board, part #BN44-00162A.  I prefer to not replace individual components parts to make the repair.  Two questions:
1.  Do you sell the SMPS board?
2.  If not, can you repair the board if I bring it in?  (I'm a little west of Ft Worth.)

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Coppell TV Repair:

1)      Yes , I believe we have at least one at the moment. There are number of different board models that would do the job and I know we have at least one in working mode, but I also know I have at least three people about to drop by and maybe swap their bad board (if bad) with a good one

2)      Yes we do repair them whenever we can (we usually can). But the really important question here is

3)      Why do you think it is the power board that is bad and not , say, the trio of the Y-Main and the two buffers? Those fail way more often in your TV.

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Customer:

Thank you for responding so fast.

I confess to being fairly electronics-dumb.  My guidance so far has been reviewing help websites (fixya) and going through others' troubleshooting steps.  I'm pretty good at soldering wires under the hood of a car, but soldering PCB is WAY beyond my abilities.  I was going to just replace the board rather than taking a chance on replacing components and then burning out the board anyway.

Here's the rundown of the problem:

The entire screen unexpectedly went black but sound remains.  It appears black, not dim.  I did the usual "wait and retry" but there is no change.

I removed the back cover and inspected the 4 main boards (left side, right side, inputs board at bottom center, and the (SMPS board?) top center board that seems to be the master board that all others feed from via flat cable.  I see no signs of burning or soot.

I removed the cable from connection 807, plugged in power, turned on the TV and get normal start sound (4 ascending notes) and typical 4 slow pulses of the blue light.  No change in black screen.  I then turned off the TV and got the normal sound (4 descending notes) and the blue light stays on as it usual.  I unplugged the TV and reconnected the 807.  I repeated this process for the 808, 809, and 810 cables.  I got the same result every time.  This lead me to believe it is the SMPS board instead of one of the others.

I know that it is always a crap shoot trying to "diagnose via email", but then again, I'm sure you see this type of problem rather frequently.  Are you open today?  I'd rather not bring in the whole TV if possible, can you advise me what board(s) I should bring?  I'm more than willing to swap out plug-in components if that's what the repair entails, but when it comes to soldering boards, I'd rather leave that to you professionals.

Thanks for your help.  It is a pleasure dealing with someone local.

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Coppell TV Repair:

 

Well your conclusion is incorrect.

Based on what you say it is highly unlikely for your problem to be in the power board.

First, if the power board does not produce the output voltages it is supposed to produce then its own control logic will catch the event and shut it off to prevent further damage.

The bare fact that the TV comes on and stays on (even without an image) suggests the power board is just fine.

Second, the description you give is the most common one for a typical failure in the Y-Main board and buffers , which I told you is the most popular in those TV – the unit comes on with no screen.

I don’t have the board handy (I am at home now), but when the Y-Main is bad there are a number of connectors you can disconnect and the result would still be the same – the TV would come on with no display.

Imagine removing the wheels on a car that does not turn on because of whatever problem with the starter; it would still not start, right? You could also remove the alternator to the same effect J

You are looking at about $240 in fixes and that’s if you bring the Y-Main board and the two buffers to us. The Y-Main will have to be repaired and the two buffer boards will most likely need to be replaced.

This explanation alone is well worth $20?

Isn’t it? :-)

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Follow-up for the online post:
Hope this helps avoid this common confusing and save a little time and a few bucks.

We offer repair services for both the power board and the Y-Main board in Samsung HP-T5064 (same as Samsung HP-T5054 by the way).

A more generic way to send us boards is to use the free form for initiating a new service order:

http://www.coppelltvrepair.com/newservice .

Prices will sure change over time, but it is highly unlikely that they will go up in the near future.

We are well aware they are too high even right now, the problem is that the new buffer boards are very expensive still...and we know from long and bitter experience that this particular failure better be done right and expensive than cheap.